This invention relates to an all pneumatic vacuum gripper that has built-in sensing capabilities.
Traditionally, vacuum grippers consist of a vacuum generator (either an electromechanical vacuum pump or venturi vacuum generator), and a suction cup. To pick-up an object, the vacuum is first turned `on` and then the vacuum cup is placed on the object's flat surface to grip it which facilitates picking up of the object. To release the object, the vacuum is turned `off` and the object is separated from the vacuum cup. However, in modern factory automation machines, the size of the objects to be handled may vary from small to very large surface areas and more than one vacuum gripper may be used on the pick up arm. In these cases, all the vacuum grippers will be turned `on` every time whether the number of suction cups coming in contact with the object being picked up is one or more. Thus the energy expended remains at a constant high level and so is the ambient noise level. Also, the control circuitry always needs to be told when to turn `on` the vacuum and then to turn it `off`. Therefore there exists a need for a vacuum gripper that can sense an object under its suction cup and turn itself `on`.
While an object is being lifted and held under the suction cup, the power utilized to generate the vacuum is continuously expended. In addition, other external means of control circuitry is needed to achieve control over the sequence of operation. Therefore there exists a need for a novel vacuum gripper wherein sensing, actuation and control of the gripper is all achieved in a single device and still only a fraction of the energy is expended to perform the same work.